Wire connectors are widely used to mechanically and electrically connect electrical wires. Such devices typically include a plastic insulating cap and a conductive helical coil within the cap. In use, typically a portion (e.g., ½ or ⅜ inch) of insulation must be stripped from each of the wires to be joined. Next, the stripped ends of the wires are held parallel and twisted together securely by hand or with pliers. Then, the twisted wires are inserted into the wire connector and the wire connector is twisted clockwise around the wires, forcing the wires securely into the helical coil.
Conventional wire connectors suffer several shortcomings relating to use. First, wires must be stripped before insertion into a wire connector. Stripping is tedious, time-consuming and conducive to error. If too little insulation is stripped, the insulation may prevent securely engaging the wire in the wire connector. If too much insulation is removed, the wire may need to be trimmed to prevent uninsulated wire from extending out of the wire connector. If the device used to strip insulation from the wire cuts too deep, the wire may be severed or damaged. If the device does not cut deep enough, the insulation may be damaged but remain on the wire.
Second, mechanical loads and vibrations may tend to loosen conventional wire connectors. Loosening may lead to exposure of live wires creating a fire hazard and risk of electrical shock. Loosening may also lead to increased resistance between contacting wires, which may lead to heat generation, which may further lead to increased resistance. Continued increase in resistance and heat generation may eventually lead to an electrical fire.
Third, conventional wire connectors have a gaping entrance, leaving contained wires exposed to moisture and debris. Moisture may cause oxidation of the conductive wire core and an attendant increases in resistance and heat generation. Debris may corrode the wires or lead to current leakage.
Fourth, it is often difficult to determine when wires are fully engaged within a wire connector, i.e., when there has been positive insertion. Over tightening can damage the wires and force them out of the wire connector. If the wires were nicked during stripping, the weakened wires may break during tightening. If the wires are inadequately tightened, the loose wires may experience increased resistance leading to heat generation.
Fifth, conventional wire connectors do not provide means far determining if engaged wires carry an electric current (i.e., if the engaged wires are live). Typically, to determine if the wires are live, the wires are disengaged from a wire connector and the exposed ends are placed in conductive contact with a testing apparatus, such as an ammeter, voltmeter, test light or the like.
Thus, an insulated electrical connector for quickly and securely connecting unstripped insulated wires is needed. Preferably, the connector enables an accurate assessment of positive insertion, limits exposure to moisture and debris and resists loosening from vibrations. The connector may also include means for determining if engaged wires carry an electric current (i.e., if the engaged wires are live).